ISIS Hub Crank Interface Smoothness/Accuracy

I bought a new ISIS hub, and my cranks do not go on by hand.

All my other hubs and cranks, I push on by hand until the last 3-6mm. Then I use the crank bolt to push it up against the crank spacer.

This new hub, the crank gets stuck right away. I tried multiple cranks, and they all have this problem with this hub. Of my 5 other ISIS hubs, the others all seem “smooth” and normal.

I tried using the bolt on one side, and the crank does start to get pushed on.

Here are some videos of the hub, and also one with different brand, Nimbus hub.

Is this normal?

Would like to get some other people’s experience and thoughts especially because I spent many hours modifying the cranks I want to put on… Would rather they do not wear or get damaged from the hub and can still be used with my other unicycles.

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I looked closer at the one crank I did try to push on partway with the crank bolt.

There is clearly the aluminum being pushed away by the axle. Is it just a slightly oversized axle?

Looks like an oversized/defective hub spline to me. Where did you get it? Maybe check with the vendor.

Well, I tried filing one side a bit with 220 grit sandpaper. It didn’t help at first. After seeing the gouging/wear marks on the cranks, I took a look again. It definitely seems like there are burrs on the hub axle.

I spent more time sanding each spline on one side. I wrapped the sandpaper around the smooth bit of a 11/64" (4.37mm) drill bit end. Now my crank slides on smoothly on that side! (I wish I had a dremel for this)

I sent an email to the vendor too to see if he knows about this.

I had noticed the same thing on your photos of the cranks, and wondered if the hub axle splines had some burrs that needed to be sanded/filed off. I am so happy to learn that you were able to determine the cause, and rectify it!

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